IMAGE PROCESSING APPARATUS, RADIOGRAPHY SYSTEM, IMAGE PROCESSING METHOD, AND IMAGE PROCESSING PROGRAM

• US 20180333119A1
• Filed: 05/09/2018
• Published: 11/22/2018
• Est. Priority Date: 05/18/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: TAJIMA, Takashi
• Granted Patent: US 10,638,992 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 6/4266 characterised by using a plurality of detector units A61B6/4014 takes precedence
• CPC Class Codes: A61B 6/461 Displaying means of special interest
• CPC Class Codes: A61B 6/482 involving multiple energy imaging
• CPC Class Codes: A61B 6/505 for diagnosis of bone
• CPC Class Codes: A61B 6/5217 extracting a diagnostic or physiological parameter from medical diagnostic data
• CPC Class Codes: A61B 6/54 Control of apparatus or devices for radiation diagnosis
• CPC Class Codes: G06T 2207/10116 X-ray image
• CPC Class Codes: G06T 2207/20224 Image subtraction
• CPC Class Codes: G06T 2207/30008 Bone
• CPC Class Codes: G06T 2207/30024 Cell structures in vitro; Tissue sections in vitro
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 7/0016 involving temporal comparison
• CPC Class Codes: G06T 7/11 Region-based segmentation
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A control unit of a console acquires first radiographic image data and second radiographic image data and determines whether a reference line which satisfies a predetermined accuracy for defining a bone mass is capable of being derived, on the basis of a pixel value of an initial soft region of a DXA profile indicating a correspondence relationship between a pixel position and the pixel value in a derivation region including a soft region and a bone region in a DXA image which is a difference image between a first radiographic image and a second radiographic image and is used to derive at least one of bone density or bone mineral content. In a case in which it is determined that the reference line is capable of being derived, the control unit derives the reference line on the basis of the pixel value of the initial soft region.

Claims

1. An image processing apparatus comprising:

an acquisition unit that acquires a first radiographic image generated by a first radiation detector irradiated with radiation with a first energy level and a second radiographic image generated by a second radiation detector irradiated with radiation with a second energy level different from the first energy level from a radiography apparatus including the first and second radiation detectors in which a plurality of pixels, each of which includes a conversion element that generates a larger amount of charge as it is irradiated with a larger amount of radiation, are arranged and which are arranged in a direction in which the radiation is emitted; and

a derivation unit that derives a reference line which satisfies a predetermined accuracy for defining a bone mass, on the basis of a pixel value of a predetermined region corresponding to a soft tissue in a profile indicating a correspondence relationship between a pixel position and the pixel value in a derivation region including a region corresponding to the soft tissue and a region corresponding to a bone tissue in a difference image for derivation which is a difference image between the first radiographic image and the second radiographic image and is used to derive at least one of bone density or bone mineral content.

3. The image processing apparatus according to claim 1,

wherein the derivation unit comprises a determination unit that determines whether the reference line satisfying the predetermined accuracy is capable of being derived, and

in a case in which the determination unit determines that the reference line is capable of being derived, the derivation unit derives the reference line.

4. The image processing apparatus according to claim 3,

wherein, in a case in which the determination unit determines that the reference line is not capable of being derived, the derivation unit specifies a region corresponding to the soft tissue and derives the reference line on the basis of a pixel value of the specified region corresponding to the soft tissue.

5. The image processing apparatus according to claim 3,

wherein the determination unit determines whether the reference line satisfying the predetermined accuracy is capable of being derived, on the basis of a variation in the pixel value of the region corresponding to the soft tissue in the profile.

6. The image processing apparatus according to claim 5,

wherein, in a case in which the determination unit determines that the reference line satisfying the predetermined accuracy is not capable of being derived, the derivation unit derives the reference line on the basis of a pixel value of a region corresponding to the soft tissue which is wider than the predetermined region corresponding to the soft tissue.

7. The image processing apparatus according to claim 3,

wherein, in a case in which the profile includes a gas region caused by gas generated in a body of a subject from which at least one of the bone density or the bone mineral content is to be derived, the determination unit determines that the reference line satisfying the predetermined accuracy is not capable of being derived, and

the derivation unit derives the reference line on the basis of a pixel value of a region corresponding to the soft tissue between the gas region and the region corresponding to the bone tissue.

8. The image processing apparatus according to claim 3,

wherein, in a case in which the profile includes an artifact region caused by an artifact in a body of a subject from which at least one of the bone density or the bone mineral content is to be derived, the determination unit determines that the reference line satisfying the predetermined accuracy is not capable of being derived.

9. The image processing apparatus according to claim 3,

wherein, in a case in which a position of a bone tissue used to derive at least one of the bone density or the bone mineral content is different from a predetermined position, the determination unit determines that the reference line satisfying the predetermined accuracy is not capable of being derived.

10. The image processing apparatus according to claim 3,

wherein the determination unit determines whether the reference line is capable of being derived on the basis of a condition in which imaging conditions for generating the first radiographic image and the second radiographic image are predetermined.

11. The image processing apparatus according to claim 3,

wherein the determination unit determines whether the reference line satisfying the predetermined accuracy is capable of being derived on the basis of an inclination of the entire region corresponding to the soft tissue in the profile.

12. The image processing apparatus according to claim 3,

wherein the determination unit determines whether the reference line satisfying the predetermined accuracy is capable of being derived on the basis of whether a component caused by a scattered ray of the radiation is included in the pixel value of the region corresponding to the soft tissue in the profile.

13. The image processing apparatus according to claim 12,

wherein, in a case in which the determination unit determines that the reference line satisfying the predetermined accuracy is not capable of being derived, the derivation unit removes the component caused by the scattered ray of the radiation from the pixel value of the predetermined region corresponding to the soft tissue on the basis of a predetermined scattered ray distribution model and derives the reference line.

14. The image processing apparatus according to claim 3,

wherein, in a case in which the determination unit determines that the reference line satisfying the predetermined accuracy is not capable of being derived, the derivation unit derives the reference line, on the basis of a pixel value of a region corresponding to the soft tissue which is specified on the basis of at least one of a bone part difference image which is a difference image between the first radiographic image and the second radiographic image and in which the bone tissue is highlighted or a soft part difference image which is a difference image between the first radiographic image and the second radiographic image and in which the soft tissue is highlighted.

15. The image processing apparatus according to claim 1, further comprising:

a bone derivation unit that derives at least one of the bone mineral content or the bone density on the basis of a bone mass which is defined on the basis of the reference line in the region corresponding to the bone tissue.

16. The image processing apparatus according to claim 1,

wherein each of the first and second radiation detectors comprises a light emitting layer that is irradiated with the radiation and emits light,

the plurality of pixels of each of the first and second radiation detectors receive the light, generate the charge, and accumulate the charge, and

the light emitting layer of one of the first and second radiation detectors which is provided on an incident side of the radiation includes CsI and the light emitting layer of the other radiation detector includes GOS.

17. A radiography system comprising:

the image processing apparatus according to claim 1; and

a radiography apparatus that outputs a first radiographic image and a second radiographic image to the image processing apparatus.

2. An image processing apparatus comprising:

an acquisition unit that acquires a first radiographic image generated by a single radiation detector irradiated with radiation with a first energy level and a second radiographic image generated by the radiation detector irradiated with radiation with a second energy level different from the first energy level from a radiography apparatus including the radiation detector in which a plurality of pixels, each of which includes a conversion element that generates a larger amount of charge as it is irradiated with a larger amount of radiation, are arranged; and

a derivation unit that derives a reference line which satisfies a predetermined accuracy for defining a bone mass, on the basis of a pixel value of a predetermined region corresponding to a soft tissue in a profile indicating a correspondence relationship between a pixel position and the pixel value in a derivation region including a region corresponding to the soft tissue and a region corresponding to a bone tissue in a difference image for derivation which is a difference image between the first radiographic image and the second radiographic image and is used to derive at least one of bone density or bone mineral content.

18. An image processing method comprising:

acquiring a first radiographic image generated by a first radiation detector irradiated with radiation with a first energy level and a second radiographic image generated by a second radiation detector irradiated with radiation with a second energy level different from the first energy level from a radiography apparatus including the first and second radiation detectors in which a plurality of pixels, each of which includes a conversion element that generates a larger amount of charge as it is irradiated with a larger amount of radiation, are arranged and which are arranged in a direction in which the radiation is emitted; and

deriving a reference line which satisfies a predetermined accuracy for defining a bone mass, on the basis of a pixel value of a predetermined region corresponding to a soft tissue in a profile indicating a correspondence relationship between a pixel position and the pixel value in a derivation region including a region corresponding to the soft tissue and a region corresponding to a bone tissue in a difference image for derivation which is a difference image between the first radiographic image and the second radiographic image and is used to derive at least one of bone density or bone mineral content.

19. An image processing method comprising:

acquiring a first radiographic image generated by a single radiation detector irradiated with radiation with a first energy level and a second radiographic image generated by the radiation detector irradiated with radiation with a second energy level different from the first energy level from a radiography apparatus including the radiation detector in which a plurality of pixels, each of which includes a conversion element that generates a larger amount of charge as it is irradiated with a larger amount of radiation, are arranged; and

deriving a reference line which satisfies a predetermined accuracy for defining a bone mass, on the basis of a pixel value of a predetermined region corresponding to a soft tissue in a profile indicating a correspondence relationship between a pixel position and the pixel value in a derivation region including a region corresponding to the soft tissue and a region corresponding to a bone tissue in a difference image for derivation which is a difference image between the first radiographic image and the second radiographic image and is used to derive at least one of bone density or bone mineral content.